1. Field of the Invention
This invention relates to the interconnection of mating members and more particularly to the interconnection of such members by cam actuator means.
2. Description of the Prior Art
The publication entitled "Connector Actuator Device" by J. B. Harris, co-inventor herein, IBM Technical Disclosure Bulletin, Vol. 16, No. 9, February 1974, pages 2839-2840, describes a cam actuator device for making simultaneous connection between two mating sets of plural connectors. More specifically, it provides simultaneous mating of an area array of electrical male pin connectors to female contact connectors. For the particular application described therein, the pin connectors are part of a module member. Examples of such members are high density integrated circuit modules or chips. The female connectors on the other hand are of the bifurcated spring type. A description of one such type of female connector is contained in U.S. Pat. No. 3,915,537, "Universal Electrical Connector", John B. Harris, the aforementioned co-inventor herein, et al, assigned to the common assignee herein and incorporated herein by reference. This type, in general, has a pair of parallel aligned contact surfaces, each of which is located on one of the bifurcated resilient arms that extend upwardly from a common main body portion. For the particular application described in the publication, these identical female connectors are mounted on a planar printed circuit board in an array corresponding to the pin array with which they are to be mated. For this purpose, each female connector has a mounting stem dependent from its main common body portion. As a result, the main body portion, resilient arms and contact surfaces of each connector are in an upright position and are extended at a uniform height above the surface of the printed circuit board to which they are mounted and such that each female connector in the array is oriented in the same direction on the board.
The cam actuator device of the publication includes an elongated cylindrical shaft and an eccentric cam portion that is integrally formed on the shaft. The shaft and cam portions are configured in the form of a crank. More particularly, the eccentric cam portion, which has a much shorter cylindrical shape but is substantially the same diameter as that of the shaft, is formed at one end of the shaft. The respective center axes of the two respective cylindrical shapes, to wit: the eccentric cam portion and shaft, are parallel and offset with respect to each other. The cam portion thus protrudes in a radial direction outwardly from the shaft and extends below the end of the shaft to which it is joined. The shaft acts as the crank handle and is pivotable about the center axis of the eccentric member.
The actuator device also includes three interlinked members which are operated by the crank. The three members are referred to in the publication as a drive block, a square block and a slide plate. Briefly, the drive block is slidably mounted in a linear manner about two parallel cant edge faces of the slide plate which fits in a recess provided in the bottom of the drive block for this purpose. The slide plate has a circular hole in which the cam portion of the crank has a pivotable bearing. The shaft in turn extends upwardly from the roof of the bottom recess and through a linear elongated guide slot formed in a midsection of the drive block. The guide slot lies in a plane parallel to the plane of the slide plate and its elongated axis is orthogonal to the linear direction in which the drive block is slidable on the slide plate.
Another recess or slot is formed inwardly from the top of the drive block down to and in communication with the narrower aforementioned guide slot located in the drive block's aforementioned midsection. This upper recess is rectangular in shape and is larger and parallel to and symmetrically disposed about the narrower guide slot. The aforementioned square block is slidably mounted in the upper recess. The square block has a center circular hole through which the shaft extends upwardly for a considerable distance above the co-planar upper surfaces of the drive and square blocks.
The drive block is affixed to the array pin module member and the slide plate is affixed to a member referred to in the publication as the base connector carrier member or simply as the base member. The base member has a planar configuration. A plurality of recesses, i.e. openings, extend between the top and bottom surfaces of the base member. Each recess is equipped with one of the female spring-type connector elements. More specifically, the spring-type female connectors gain access to the recesses from the bottom side of the base member. Thus, with the female connectors in the recesses, the upper surface of the printed circuit board from which the female connector extend is in contact with the bottom surface of the base member. It should be understood that in the aforementioned publication, the printed circuit board is not illustrated.
Each of the pins which extend from the bottom surface of the module member on the other hand gain access to one of the recesses of the base member from the latter's top side. With the pins in the recesses, the bottom surface of the module member is in contact with the upper surface of the base member. With the printed circuit board and module member so assembled with the base member, the bottom surface of the slide plate is in contact with the upper surface of the planar module member. Downwardly extended mechanical connection pins affix the slide plate to the base member, the module members having openings therethrough through which these mechanical connections pass. These lastmentioned openings are sufficiently large so that the mechanical pins do not obscure the relative movement between the module member and base member next to be described.
When the printed circuit board, base and module members are initially assembled, the male pin and female connector to be mated are juxtaposed in opposite ends of the particular recess of the base member in which they are located. This provides a no-insertion force type of electrical connection. For purposes of explanation, it is assumed that the printed circuit board and base member and, hence, the slide plate are stationary. As a result, rotation, i.e. pivoting, of the shaft about the pivotal bearing causes the drive block and module member to move relative to the base member. More specifically, the moment created by the rotation of the shaft provides a radial force component which causes the drive block to slide across the slide plate in one direction and a tangential force component which causes the square block to slide in the upper recess of the drive block in an orthogonal direction. As a result, the actuator device causes each pin to move simultaneously in the same linear direction as the drive block. As a result, each pin is placed between and in wiping contact with the two contact areas of its associated female connector with which it is aligned, thereby effecting the mating and hence, electrical interconnection of the pin and its female connector. At the same time, however, any lateral movement of the pin relative to the contact areas is mitigated by the kinematics of the actuator device.
The aforedescribed device of the prior art publication has several disadvantages. The number of interconnected and machined parts required for the device made it rather complex. Its complexity, furthermore, makes it difficult and costly to fabricate. Moreover, it causes the base member to be placed under undesirable stress, as will be explained in greater detail hereinafter when describing the present invention. Furthermore, should the actuator device be continued to be rotated, i.e. pivoted, in the same rotational direction after the mating was effected, it continued to drive the pins in the same linear direction and thus, the mated connectors were capable of placing the base member under further undesirable stress. Moreover, the elongated shaft, if accidentally skewed from the normal, i.e. perpendicular, would cause the parallel relationships between the respective planes of the module member, printed circuit board and/or base member to assume a non-parallel relationship which in turn was susceptible to misaligning the pins with their respective female connectors. As a result, if a mating operation were to be initiated when a non-parallel relationship existed, damage and/or failure of the members to be mated could result and/or an improper mating could occur. Moreover, in this prior art actuator device, the shaft and cam portion was such that it could not be readily removed from the assembly and, hence, a separate shaft and cam portion was required to be dedicated for each such assembly. Moreover, because the shaft and cam portion remained with the assembly, it was subject to accidental skewing resulting in the aforementioned non-parallel planar relationships and harmful effects thereof.